The Hostel is actually a cave found by Chase Stein in Bronson Canyon, which is located within Griffith Park. Chase placed a sign saying that warning of Gamma testing, to deter anyone else from entering the cave. Inside the cave is a collapsed mansion, one that fell during one of California's many earthquakes. When Chase and his friends, the Runaways, needed a place to hide and stay, they went to the Hostel.
They erroneously invited a fellow runaway teenager to join them and brought him to the Hostel. That teenager, Topher, revealed himself to be a vampire and tried to kill everyone, though he was defeated instead. That caused the Runaways to be even more careful about who they allow or tell into the Hostel.
Their headquarters were compromised by the traitor on the Runaways, who revealed where they were hidden. Lieutenant Flores and a squad of police officers raided the Hostel, which led to a fight that caused a cave-in, making the Hostel ineffective as sanctuary. The Runaways fled the Hostel, never seeing it again.